Britain's Got Talent: The blonde violinist who dazzled Simon Cowell is used to the celebrity life with her boyfriend from band McFly

By JAMES TAPPER

She is one quarter of the glamorous girl group bidding for stardom on the television show Britain's Got Talent.

But blonde violinist Izzy Johnston, who dazzled judge Simon Cowell as part of the sexy string quartet Scala, is already used to the demands of celebrity.

Unknown to millions of viewers, she has been dating boy band star Harry Judd of McFly for two-and-a-half years.

The 22-year-old singer ran the London Marathon the day after Scala's performance on the hit ITV show to raise money for Izzy's disabled brother Rupert.

So far, Harry's efforts have brought in £25,000 for the Brain Injury Rehabilitation Trust (BIRT) and the Teenage Cancer Trust.

BIRT helped Rupert on the long road to recovery after he suffered brain damage in a car accident 12 years ago, and since 2002 he has lived at Kent House, the trust's residential rehabilitation centre in Aylesbury, Buckinghamshire. Izzy, 24, said: "Harry and I are very happy together. It's probably just a coincidence that we are both musical. I introduced him to Rupert because he is a big part of my life."

She and Harry met in 2005 when Scala supported McFly on tour.

The four girls impressed judges Cowell, Piers Morgan and Amanda Holden in the first episode of the show last week. "Harry's so supportive, always encouraging," said Izzy.Harry, who has had seven No1 singles with McFly, is also keen to help Rupert, 30, who was severely injured after his car ran into the back of an articulated lorry on the M25 in 1996.

"Harry thinks Rupert is wonderful," Izzy said. "After the crash he had to stay in hospital for a year.

"He was in intensive care, slipped into a coma, got MRSA and then his lung collapsed from pneumonia. The doctors asked my parents if they wanted to turn the life support machine off.

"Rupert's a miracle. Sometimes he can be really funny. On Saturday he was so excited after seeing the show, he rang me to tell me, 'They liked your legs, didn't they Izzy.'

"He's a wonderful character. He's blind in one eye and has metal plates in his face but amazingly his mouth and jaw were not affected so he plays the French horn.

"We visit him about twice a month and take him out for a pizza and bowling and a pint in the pub." Donations to Harry's marathon run can still be made through his website.